The following files are in the archive:

SIMM.PLT        SCOOTER-PCB file
SIMM1270.IMG    IMG at 1270dpi
SIMM_300.IMG    IMG at 300dpi
SIMM_NEC.BIN    Printing file for NEC-compatible pin-printers
SIMM_LJ.BIN     Printing file for Laserjet
SIMM.GEM        PCB (printed circuit board) view from below

If anyone would like to have a different printing file, they should 
write to me. MausNet-address follows at end.

Which SIMMs one uses is fairly irrelevant; I've had various ones in,
3 chip, 9 chip versions, above all one can also use those with 8 bits 
on the Atari, which are sometimes sold cheaply by MAC-owners.

Where the PCB is marked A0, you also place the other address lines in 
ascending order.

The address lines are connected via 33 Ohm series resistors, the 
RAS/CAS lines via 68 Ohm.

The line /W is normally connected without a series resistor.

Though the PCB has room for resistors for the control lines, but - 
as an expert told me - these are better placed close to the MMU.

The SIMMs can not be inserted the wrong way round into their sockets, 
they should have the chips facing the power connections. The two inner 
SIMMS form Bank 0, the outer two SIMMs Bank 1.

The +5V and ground connections cannot be thick enough. I, for instance,
had to fit 4 ground and 3 +5V wires of 0.75mm in order to be able to  
use the RAM expansion without errors.

Here follows the pinout of the MMU (from ST-Computer 2/92 and without 
any guarantee):

23=/W
08=/RAS0    Bank 0
07=/CASOL   Bank 0
06=/CAS0H   Bank 0
18=/RAS1    Bank 1
21=/CAS1L   Bank 1
22=/CAS1H   Bank 1
59=MAD0
58=MAD1
57=MAD2
56=MAD3
55=MAD4
54=MAD5
60=MAD6
62=MAD7
63=MAD8
66=MAD9  (Pin 64 for PLCC-MMU, all ?other? pins match there too)

All information for the SMD-MMU and without guarantee.

The data lines are connected directly to the Shifter (that is the IC 
under the tin lid): Pins 3-10 (data lines 0-7) and pins 12-19 
(data lines 8-15), without series resistors.

To disable the old memory in the ST, one should connect the control 
lines (/RAS and /CAS) via series resistors to +5 V. If there are 
problems with the memory extension, one has to desolder one side of 
the resistors so that the old memory is completely isolated. 
[Translator's note: Not clear which resistors are meant here - 
presumably those mentioned above, but this is not explicit in the 
original text.]

I offer no guarantees for the correcteness of the contents of this 
text. Those that have problems with the extension can get in touch  
with me. I can be reached in the MausNet: Romeo Rakow @CB

